Temperature control



Nov. 6, 1934. R. M. HEINTZ 1,979,546

TEMPERATURE CONTROL Filed Dec. 9, 1952 PEFR/GERATl/VG SYSTEM INVENTOR, RALPH M. HE/NTZ.

A T'TORNE Y ing an oscillating crystal at a constant tempera- Patented Nov. 6, 1934 PATENT QFFHQE TEMPERATURE CONTROL Ralph M. Heintz, Palo Alto, Calif., assignor to Heintz & Kaufman, Ltd., San Francisco, Calif,

a corporation of Nevada c Application December 9, 1932, Serial No. 646,403

- Claims. (01. 62 -7) My invention relates to a temperature control,

and more particularly toa device which utilizes the temperature" regulation provided by the melting or solidification of a crystalline substance.

Among the objects of myinvention -are:To provide a constant temperature bath; to provide a device for maintaining an objectat a constant temperature; to provide a device for maintainture; and to provide asimple' device operative to break an electrical circuit upon congelation of a crystalline substance.

Other objects of my invention will be apparent or will be specifically pointed out in the description forming a part of this specification, but I do not limit myself to the embodiment of my invention herein described, as various forms may be adopted within the scope of the claims.

Referring to the drawing: V Figure l is a longitudinal view, partly in section and partly in elevationof a temperature control bath.

Figure 2 is a face View in elevation of a circuit breaker operative on congelation '0: the'liquid in the bath,.taken from-a planeindicated by the line 22 in Figure 1.

While there are many objects which it is desirable to maintain at a constant temperature, I

have shown my invention as applied to. a quartz I have provided a device in which such a crystal,

or other objects as desired, may be kept and maintained at a uniform and unvarying temperature.

Broadly speaking my invention comprises a container filled with a crystalline substance, liquid at room temperature. I provide means for maintaining this liquid in a partially congealed or frozen state, and place my object to be maintained at a constant temperature in the unfrozen portion. Inasmuch as the congelation or melting is never allowed to be completed the temperature will not vary, as when a crystalline substance undergoes either melting or solidifying, its temperature remains constant from the instant that melting or solidifying begins, until the process is completed.

In the drawing, which represents a preferred embodiment of my invention, employing water as the crystalline substance, a double-walled container 1 is mounted on a base 2, and filled with a quantity of water 3, preferably distilled.

A brine coil 4 is placed in the inter-wall space, close to the inside of the container, and the remainder of the space is filled with agood heat insulator 5 such as ground cork, asbestos wool, or the like.

The brine coil is connected to a refrigerating system, so designated on the drawing, by means of pipe fittings 6-6. This refrigerating system is electrically operated and has, emerging from it, energizing supply wires 7 and 8.

A 'quartz crystal 9, together with its contact electrodes 10 and 11, is enclosed in a control box 12 held in the center of the container by conduits 13 and 14 through which run crystal leads l5 and 16 by means of which the crystal may be 70 connected in a vacuum tube or other circuit. All precautions are taken to prevent any liquid from entering the control box.

Mounted on the upper rim of the container is a circuit-breaker mechanism comprising a motor 1'? having motor leads l8 emerging therefrom, which'may be directly connected to alternating current mains 19. This motor, preferably of low i power, may be designed to run at a slow speed, or may be geared down to a drive-shaft 20 which carries on its outer end a breaker disc 21, of insulating material such as bakelite or lava.

The breaker disc has a central stud 22 to which ,is loosely fitted a contact arm 23 long enough to enter the waterto a substantial depth when rotated, and provided with a drip-cup 24, and an arm contact 25. I

A contact bracket 26 is fixed to the disc, extending parallel to the arm, provided with a bracket contact 27, and is connected to a metal rim 28 by a link 29. The arm contact and the bracket contact are directly opposed, and are held together firmly by a spring 30, attached at one end to a short arm stub 31 extending away from the main portion of the arm on the other side of the central stud 22, and to a spring stud 32 attached to the disc 21. The two contact points thus make electrical connection between the rim 28 and the arm.

I prefer to make the central stud 22 the end 10 of the drive-shaft 20, and make the drive-shaft of metal, so that I may utilize the motor frame as a means of making connection to the arm.

The extreme end of the contact bracket 26 is provided with an insulating stop-bar 33, passing through a boss 34 in the arm and carrying a stop 35 at its end. This stop prevents the contacts from opening too far and acts to stall the motor, as will be described later.

Electrical connection is made to the rim 28 by rim 28, brush 36 and post 3'7 back to the mains through wire 39.

When the mains are energized, the refrigeration system will start up, as the contacts and 27 are closed, and the motor 1'7 will start rotating.

I prefer to rotate the arm 23 about once'per' second and the motor mechanism 17 may well be that of the well known synchronous clock. It is however perfectly feasible to operate the en tire device from D. C. mains, using proper rho- 1 tors, as the exact time of arm rotation is immaterial.

Inasmuch as the water offersno resistance to the arm as it rotates, the contactswill' remain closed. Freezing of the water wi11"sta r t when the temperature of the entire amount of water reaches 32, and the freezing, or congelation will take place progressively out from the walls of the container as indicated by the dotted line 40.

When the frozen crystals reach the point where the arm is rotating, which takes place before the congelation reaches the control box, the arm will be blocked by ice and will cease rotating. The disc, however, will keep on rotating, against the spring 32, open the contacts 25 and 27, until it also is stopped by the. stop 35 hitting the boss .34. The motor 1'7 then. stalls, and will remain stalled until the ice crystals melt. In the meanthe control box will also be time, the opening of the contacts has stopped the arm, the arm will start rotating again andthe contacts will close. This cycle is repeated to the end that there will always be a layer of ice around the insideof the container, withunfrozen liquid in the center. 'Ifhe temperature will thus ,be kept accurately, at'3 2, and objects placed in maintained uniformly at that temperature;

I claim:

1. A constant temperature bath comprising a container for receiving a fluid', means for freezing a portion of said fluid, means for preventing the,

remaining portion irom freezing, and a receptacle for an article to be kept ata constant temperature positioned to. be surrounded by said unfrozen portion.

2. A constant temperature bath comprising a container for receiving a fluid, means for freezing a portion of said fluid, means for preventing the remaining portion from freezing, and a receptacle for a quartz crystal positioned to be surrounded by said unfrozen portion.

3. A constant temperature bath comprising a container having walls, refrigerating coils in said walls, fluid in said container, electrically-driven refrigerating means abstracting heat from said coils to freeze said liquid, means for supplying current to said refrigerating means, means operating to break said supply current to said refrigerating; means when a portion of said liquid is frozen, and a receptacle for a temperature effected portion of an oscillatory-electrical system positioned to be surrounded by the unfrozen portion'of said liquid.

4,; 9, constant temperature bath comprising a containe having walls, refrigerating coils in said walls, fluidin said container, electrically-driven refrigerating means abstracting heat. from said coils to freeze said liquid, means for, supplying current to'said refrigerating means, means opera ating to break said supply current to-saidgrefrigeratin'g means when a portion. of saidliquid is frozen, means for closing. said circuit when-the, frozen portion starts to melt, and a receptacl'elfor a temperature effected portion. of'an oscillatory,- electrical system positioned to be surrounded? by the unfrozen portion of said liquid,

5. A constanttemperature bath comprising a container having walls, refrigerating coils insaid. walls, fluid in, said container, electrically-driven refrigerating means abstracting heat from said.

coils to freeze said liquid, means for supplyingcur-- rent to said. refrigerating means, and an arm mov-. able through said liquid, said arm carrying con,- tacts adapted to be, broken when; said arm is stopped by congelation' of, said liquidsaid refrigerating meansbeing controlledby current passing through said contacts.

6. A constant temperature bath comprising a container having walls,,refrigerating coils in said walls, fluid in said container, electrically driven refrigerating; means abstracting heat from said coils to freeze said liquid, means forsuppl'ying current to saidrefrigerating means, an arm moviable through said liquid; said arm: carrying con-. tacts adapted to be broken when said arm' is stopped by congelationofsaid liquid, saidrefrigerating means being controlled by currentpassing through said contacts, and means for closing said contacts when saidarmis freed bythe meltingfof said congealed liquid; 

